can i use my gpu as ram

No

No you can't, they are completely different things.

i will third that one.no.what system and ram do you have?

The VRAM CAN BE USED AS RAM-DISK what a heck guys stop lying the people, the only thing that differs is the:
1. AMOUNT OF VRAM on the card which windows easyly sees it thru it's installed video card driver;
2. GPU TYPE let's say G86 does not have same VRAM CONTROLLER as AMD 7780 which is driven of course BY THE DRIVER and THE GPU.
3. VRAM TYPE AND INTERCONNECTION
- DDR GDDR2 GDDR3 GDDR4 GDDR5.. GDDRx.
- 32bit 64bit 128bit 256bit 384bit 448bit 512bit and so on which gives the VRAM SPEED 5GB/s to 500GB/s and even more 1TB/s 10TB/s in the near future.(YES 500 GIGABYTES PER SECOND!!!!)
4.THE MODIFIED DRIVER for each and every type of video card, for example for nVidia FX5700 uses another driver than GTX8800
5.THE OPERATING SYSTEM xp, vista,7,8,linux,solaris,mac os.......win95......32bit 64bit
6.The only BIG PROBLEM is that it's more complicated to edit each card drivers separately (more bugs,another problems), because can be easy to crash systems or even damage the video card itself, when ramdisk uses almost the same driver (32bit vs 64bit and the supported operating systems) on any system which makes things much more simple and this makes the main difference.
so there must be different edited VRAM driver for each card so they can be used as VRAMDISK without affecting anything on the system, like the displayed image and so on.
Everything reduces to video card model and the modded driver that should fit perfectly for that type of that card and the application to control whenever you want to play a game or edit a video and so on to disable the vramdisk and let the system make use of it, and to control how much of the vram should be used just like normal ramdisk software.
The real advantages for using vram as ramdisk is the speed achieved which can be used for faster decryption and other stuff, not the amount of memory (of course under 128Mb there's no point working for that drivers).
There are supercomputers running gpu type computations with lots of tesla cards using a part of their vram as vramdisk for caching and swapping, because it's 10x-20x faster than any ultimate expensive super-over-clocked ram.
Don't tell me that a 5 PETA-BYTE/SECOND memory bandwidth supercomputer uses only "normal" RAM TO ACHIEVE THAT SPEED!.
EXAMPLE: http://www.nvidia.com/object/tesla-servers.html
Wouldn't be nice for a Tesla K40 288GB/s memory bandwidth to use some of the 12GB of it's VRAM and 2880 CUDA CORES?
And newer Intel Phi Coprocessors which use GDDR5 (8GB) as RAM.
http://www.cray.com/Products/Computing/CS/CS-AC/Specifications.aspx